Scientists know very little about the pocket shark—they're not even sure what it keeps in its pockets—but a Gulf of Mexico catch has doubled the number of known specimens. At 5.5 inches, the species is small enough to fit in your pocket, the National Oceanic and Atmospheric Administration says, but it got its name from the two deep pockets it has next to its front fins. The only previous specimen was caught off the coast of Peru 36 years ago and is now in a Russian museum, reports the AP. The new catch was a recently born male, and it "has us thinking about where mom and dad may be, and how they got to the Gulf," NOAA biologist Mark Grace says.
The rare creature was caught in the Gulf on a 2010 research trip and spent three years sitting in Grace's freezer waiting to be identified, reports the AP. Scientists have classified the species as the only member of the genus Mollisquama in the family Dalatiidae. That family includes "cookiecutter sharks," and researchers believe the pocket shark may feed in the same way: by removing plugs of flesh from larger creatures, the NOAA says. The pockets are still a mystery, but Grace suspects they may secrete a glowing fluid, the AP notes. (Read more discoveries stories.)